Recently I received an email from Dan Lepard, who is to baking what Lewis Hamilton is to Formula One. What Lepard doesn't know about the miraculous interplay of live yeast and flour isn't worth knowing. He was the first pastry chef at Fergus Henderson's St John and has written some of this country's most important texts on bread-making. (He also happens to be a talented photographer, as anybody who has a copy of Giorgio Locatelli's magisterial Made in Italy will know; Lepard shot the debauched food porn that illustrates its pages. This must surely contravene some protectionist EU policy, forbidding people from being too talented in too many disparate professions.)

Lepard was getting in touch to tell me that he had recently been directed to what he had been told was a source of near-perfect pizzas. 'I've been there, too,' he said. 'And I have to agree.' This was remarkable news, not least because the restaurant in question, Donna Margherita, was not some grand, flouncy gastro palace, but a humble trattoria on a scuffed and smudged stretch of Lavender Hill in south London.

The notion of the perfect pizza is, of course, controversial. We can all agree that the sweaty, oily duvet of fat-soaked dough served up at Pizza Hut is an abomination that deserves to be whipped with a cat-o'-nine-tails as a warning to others. And if you don't agree, go down the shops and buy a different newspaper. You'll be much happier that way. Some people hate Pizza Express. Personally, I think their product, while hardly top dog, is reliable and their service spot on for the market it serves. (I take my kids to the local one a lot. So shoot me.) Elsewhere in the high street I think Strada has done good work introducing something authentically wood-fired to a mass market.

But the perfect pizza is another creature altogether, as rare as a sexy politician or a footballer with opinions on the works of Proust. I asked Lepard what he thought makes for this quasi-mythical food item. 'Flour, time and Italians,' he said. 'British flour is designed to be moist and heavy, because that's what we want for our tin loaves. To make a good pizza you need proper Italian double zero. Then you need to make the dough early and leave it to rise for a few hours. And the final thing is the people who make it. They have to be Italian.'

Donna Margherita, which has been open for four years, clearly has all these things. It specialises in the food of southern Italy and 90 per cent of its ingredients come from there. (I know this because when I phoned to book the owner gave me the full marketing spiel, even though I told him I had already asked for a table so he didn't need to do the hard sell.) It is not much to look at, which is to say it looks exactly like almost every other traditional Italian gaff in this country. The menu is also unsurprising. A dish of mussels, in a potent broth with garlicky croutons, was solid; an overdressed beef carpaccio, heavy on the lemon juice, was less so. Friarelli - Italian greens - in olive oil and chilli was a lovely, bitter, brassic plateful.

We also ordered some of their garlic bread, essentially a flavoured pizza base, and the reason for Lepard's excitement quickly became clear. It arrived hot, was light, thin and crisp, and littered with smoky bubbles that crunched against the roof of the mouth to release sudden puffs of the smoky oven's flavour. The balance of herbs to garlic was spot on, and quickly the bread disappeared. And the reason I am talking up this garlic bread, the reason I am eulogising it is - bugger, damn, blast - the pizzas themselves didn't quite deliver. In short, this review is all foreplay and no consummation.

I ordered a Romana, that simple combination of tomato, mozzarella, anchovies, olives and capers - lots of sharp, salty flavours - and it was merely OK. It looked the part but I fear it had lingered after leaving the oven, and the all-important base lacked the whoosh of freshness of the garlic bread. The menu lists various classics and two, weirdly, called the Gay and the Lesbica. I have no idea why they have these names. Both are half-and-half pizzas. (Would not the Hermaphrodite be more appropriate?) The Lesbica, which my companion ordered, was basil, ham and mushrooms on one side, and rocket and Parmesan on the other. It, too, was less than piping hot, and as a result relentless under its rustling shrubbery of fresh green leaves.

But that garlic bread gives me hope, as does Dan Lepard's recommendation. I genuinely don't think he would have talked up the pizzas here if he hadn't found them to be great. So excuse a shameful descent into filthy democracy by this critic. Usually I wouldn't give a fig for the opinions of anyone who isn't me, but I would genuinely love to know what others think of the pizzas at Donna Margherita. Please email me and I'll report your findings on our blog.